[iOS] Extract presentation from BookmarkPromoController

BookmarkPromoController is a helper for view objects that
currently displays UI via the dispatcher (eg, -showSignin:).
We want to extract presentation actions out of this
pseudo-view layer and into the VC layer.

Related to crrev.com/c/756362

Bug: 
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Id4a97c11f857a448fa8f51a50a3e2c06f4d0426a
Reviewed-on: https://chromium-review.googlesource.com/771698Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517110}

ios/chrome/browser/ui/bookmarks/bookmark_home_view_controller.mm

@@ -141,10 +141,10 @@ std::vector<GURL> GetUrlsToOpen(const std::vector<const BookmarkNode*>& nodes) {
 
     // It is important to initialize the promo controller with the browser state
     // passed in, as it could be incognito.
-    _bookmarkPromoController =
-        [[BookmarkPromoController alloc] initWithBrowserState:browserState
-                                                     delegate:self
-                                                   dispatcher:self.dispatcher];
+    _bookmarkPromoController = [[BookmarkPromoController alloc]
+        initWithBrowserState:browserState
+                    delegate:self
+                   presenter:self /* id<SigninPresenter> */];
   }
   return self;
 }

ios/chrome/browser/ui/bookmarks/bookmark_promo_controller.h

@@ -7,7 +7,7 @@
 
 #import <UIKit/UIKit.h>
 
-@protocol ApplicationCommands;
+@protocol SigninPresenter;
 
 namespace ios {
 class ChromeBrowserState;
@@ -40,7 +40,7 @@ class PrefRegistrySyncable;
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState
                             delegate:
                                 (id<BookmarkPromoControllerDelegate>)delegate
-                          dispatcher:(id<ApplicationCommands>)dispatcher;
+                           presenter:(id<SigninPresenter>)presenter;
 
 // Presents the sign-in UI, presenting from |baseViewController|.
 - (void)showSignInFromViewController:(UIViewController*)baseViewController;

ios/chrome/browser/ui/bookmarks/bookmark_promo_controller.mm

@@ -15,8 +15,8 @@
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/pref_names.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
-#import "ios/chrome/browser/ui/commands/application_commands.h"
 #import "ios/chrome/browser/ui/commands/show_signin_command.h"
+#import "ios/chrome/browser/ui/signin_interaction/public/signin_presenter.h"
 #import "ios/chrome/browser/ui/ui_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -52,8 +52,8 @@ class SignInObserver;
   bool _promoDisplayedRecorded;
 }
 
-// Dispatcher for sending commands.
-@property(nonatomic, readonly, weak) id<ApplicationCommands> dispatcher;
+// Presenter which can show signin UI.
+@property(nonatomic, readonly, weak) id<SigninPresenter> presenter;
 
 // Records that the promo was displayed. Can be called several times per
 // instance but will effectively record the histogram only once per instance.
@@ -97,7 +97,7 @@ class SignInObserver : public SigninManagerBase::Observer {
 
 @synthesize delegate = _delegate;
 @synthesize promoState = _promoState;
-@synthesize dispatcher = _dispatcher;
+@synthesize presenter = _presenter;
 
 + (void)registerBrowserStatePrefs:(user_prefs::PrefRegistrySyncable*)registry {
   registry->RegisterBooleanPref(prefs::kIosBookmarkPromoAlreadySeen, false);
@@ -106,11 +106,11 @@ class SignInObserver : public SigninManagerBase::Observer {
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState
                             delegate:
                                 (id<BookmarkPromoControllerDelegate>)delegate
-                          dispatcher:(id<ApplicationCommands>)dispatcher {
+                           presenter:(id<SigninPresenter>)presenter {
   self = [super init];
   if (self) {
     _delegate = delegate;
-    _dispatcher = dispatcher;
+    _presenter = presenter;
     // Incognito browserState can go away before this class is released, this
     // code avoids keeping a pointer to it.
     _isIncognito = browserState->IsOffTheRecord();
@@ -145,7 +145,7 @@ class SignInObserver : public SigninManagerBase::Observer {
       initWithOperation:AUTHENTICATION_OPERATION_SIGNIN
             accessPoint:signin_metrics::AccessPoint::
                             ACCESS_POINT_BOOKMARK_MANAGER];
-  [self.dispatcher showSignin:command baseViewController:baseViewController];
+  [self.presenter showSignin:command];
 }
 
 - (void)hidePromoCell {